Concrete pipes are employed in various civil engineering and architectural applications, such as culverts and building support structures, because of their high strength to weight ratio. Generally, concrete pipes are constructed by placing a reinforcing metal frame inside a mold or framework which is adapted to receive and cure concrete. The resultant concrete pipe generally includes a first end, a second end, an outside surface, an inside surface, and a reinforcing frame positioned therebetween that extends along a longitudinal axis between the first end and the second end.
One drawback of the construction of concrete pipes is that the placement of the metal frame relative to the outside and inside surfaces of the pipe may be altered as a result of the forming process. More specifically, it is desirable to maintain the radial location of the metal frame with respect to the internal diameter and outer diameter of the finished concrete pipe, wherein the theoretical structural behavior of the finished product is well characterized. If, for example, the metal frame is offset in the form during fabrication the pipe will have varying material properties, which may lead to localized cracking or frame buckling.
Thus, there is a long felt need in the field of concrete pipe fabrication to ensure that the reinforcing material used therein is located in the proper predetermined location subsequent to the forming operation, thus increasing the probability that the finished product behaves as theoretically expected. The following disclosure describes a device and method for selectively engaging a reinforcing frame to maintain its radial location within the concrete form during pipe fabrication.